Animals, like all organisms, are at different levels of organization. One of them is cellular, and its typical representative is the amoeba protea. The features of its structure and vital activity will be considered in more detail below.
Subdomain Unicellular
Despite the fact that this systematic group unites the most primitive animals, its species diversity already reaches 70 species. On the one hand, these are indeed the most simply arranged representatives of the animal world. On the other hand, these are simply unique structures. Just imagine: one, sometimes microscopic, cell is able to carry out all vital processes: respiration, movement, reproduction. Amoeba Proteus (photo shows her image under a light microscope) is a typical representative of the Simplest Kingdom. Its dimensions barely reach 20 microns.
Amoeba Proteus: a class of simple animals
The species name of this animal itself indicates the level of its organization, since Proteus means "simple." But is this animal so primitive? Amoeba Proteus is a representative of the class of organisms that move with the help of intermittent outgrowths of the cytoplasm. The colorless blood cells that form the human immunity move in a similar way. They are called white blood cells. Their characteristic movement is called amoeboid.
What environment does the amoeba protea live in?
This simplest organism prefers to live in fresh and salty water bodies. Waterlogging conditions are especially favorable for him, since the process of decay involves the presence of a large number of bacteria that feed these simple organisms. However, its dysenteric appearance feels comfortable in the lumen of the human intestine. At first glance, it may seem that this is a parasitic species. But this opinion will be erroneous. Being in the intestines, it feeds on a variety of bacteria and does no harm to humans. But if the intestines are affected, the amoeba penetrates the blood vessels and begins to feed on red blood cells. In this case, sores form on the walls. You can become infected with a dysenteric amoeba by using raw water, dirty vegetables and fruits.
The amoeba protea inhabiting contaminated water bodies does no harm to anyone. This habitat is the most suitable, because in it the simplest takes its important role in the food chain.
Structural features
Amoeba Proteus is a representative of the class, or rather the kingdom of the Unicellular. Its size barely reaches 0.05 mm. With the naked eye, it can be seen in the form of a barely noticeable jelly-like lump. But all the main organelles of the cell will be visible only under a light microscope at high magnification.
The surface apparatus of the amoeba protea cell is represented by a cell membrane, which has excellent elasticity. Inside is a semi-liquid content - the cytoplasm. She moves all the time, causing the formation of pseudopods. Amoeba is a eukaryotic animal. This means that her genetic material is contained in the nucleus.
Protozoan movement
How does the amoeba protea move? This occurs with intermittent outgrowths of the cytoplasm. She moves, forming a protrusion. And then the cytoplasm flows smoothly into the cell. Pseudopods retract and form elsewhere. For this reason, the amoeba protea does not have a constant body shape.
Nutrition
Amoeba Proteus is capable of phage and pinocytosis. These are processes of absorption of solid particles and liquids by a cell, respectively. It feeds on microscopic algae, bacteria, and similar protozoa. The amoeba protea (the photo below demonstrates the process of capturing food) surrounds them with its pseudopods. Next, the food is inside the cell. Around it, a digestive vacuole begins to form. Thanks to digestive enzymes, the particles break down, are absorbed by the body, and undigested residues are removed through the membrane. By phagocytosis, blood leukocytes destroy the pathogenic particles that penetrate the body of humans and animals every moment. If these cells did not protect organisms in this way, life would be practically impossible.
In addition to specialized nutrition organelles, inclusions can also be in the cytoplasm. These are inconsistent cell structures. They accumulate in the cytoplasm when there are necessary conditions for this. And they are spent when a vital need arises in this. These are starch grains and droplets of lipids.
Breath
Amoeba protea, like all unicellular organisms, does not have specialized organelles for the implementation of the respiration process. It uses oxygen dissolved in water or another liquid when it comes to amoeba living in other organisms. Gas exchange occurs through the surface amoeba apparatus. The cell membrane is permeable to oxygen and carbon dioxide.
Breeding
Amoeba is characterized by asexual reproduction. Namely, cell division in two. This process is carried out only in the warm season. It takes place in several stages. The core is divided first. It is stretched, separated by a constriction. As a result, two identical ones are formed from one core. The cytoplasm between them is torn. Its sections are secluded around the nuclei, forming two new cells. The contractile vacuole appears in one of them, and in the other its formation occurs anew. The division occurs through mitosis, therefore, daughter cells are an exact copy of the mother. The process of reproduction of amoeba occurs quite intensively: several times a day. So the life expectancy of each individual is very small.
Pressure regulation
Most amoebas live in an aquatic environment. A certain amount of salts is dissolved in it. Much less than this substance in the cytoplasm of the simplest. Therefore, water should flow from an area with a higher concentration of the substance to the opposite. These are the laws of physics. In this case, the body of the amoeba should have burst from an excess of moisture. But this does not happen due to the action of specialized contractile vacuoles. They remove excess water with salts dissolved in it. Moreover, they provide homeostasis - maintaining the constancy of the internal environment of the body.
What is a cyst?
Amoeba proteus, like other protozoa, in a special way adapted to experiencing adverse conditions. Its cell ceases to feed, the intensity of all life processes decreases, the metabolism stops. Amoeba stops sharing. It is covered with a dense shell and in this form tolerates an unfavorable period of any duration. This happens periodically every fall, and with the onset of heat, the unicellular organism begins to breathe intensively, eat and multiply. The same thing can happen in the warm season with the onset of drought. The formation of cysts has another meaning. It lies in the fact that in this state, the amoeba carries the wind over considerable distances, resettling this biological species.
Irritability
Of course, these simple single-celled organisms are not talking about the nervous system, because their body consists of only one cell. However, this property of all living organisms in the amoeba protea manifests itself in the form of taxis. This term means a response to the action of various stimuli. They can be positive. For example, an amoeba clearly moves toward food objects. This phenomenon can essentially be compared with animal reflexes. Examples of negative taxis are the movement of amoeba protea from bright light, from areas of increased salinity or mechanical irritants. This ability is primarily protective value.
So, the amoeba protea is a typical representative of the subgenus Protozoa or Unicellular. This group of animals is the most primitively arranged. Their body consists of one cell, however, it is able to perform the functions of the whole organism: breathe, eat, multiply, move, respond to irritations and adverse environmental conditions. Amoeba Proteus is part of the ecosystems of fresh and salt bodies of water, but is also able to inhabit other organisms. In nature, it is a participant in the cycle of substances and the most important link in the food chain, being the basis of plankton in many reservoirs.